I'm 'covering all my bases' because that's the truth of the matter. There was a variety of objects. If you think I'm telling you this to pull wool over your eyes, you are incorrect.
... and your assertion that stones that float are not Gallstones is such a black and white assertion to be laughable. I think it's safe to assume that no two stones would be the same. Some have a higher density, some a lower density. Some float, some sink. To say that all stones must sink is incorrect.